|Title|Year|Platform|Developer|Publisher|
|---|---|---|---|---|
|SWAT 3: Close Quarters Battle|1999|Microsoft Windows|Sierra Northwest|Sierra Entertainment|
|SWAT: Global Strike Team|2003|PlayStation 2, Xbox|Argonaut Games|Argonaut Games Sierra Entertainment|
|SWAT 4|2005|Microsoft Windows|Irrational Games|Vivendi Universal Games Sierra Entertainment|
|SWAT 4: The Stetchkov Syndicate|2006|Microsoft Windows|Irrational Games|Vivendi Universal Games Sierra Entertainment|
|SWAT Force|2006|Mobile phones|Kaolink|Vivendi Games Mobile|
|SWAT: Target Liberty|2007|PlayStation Portable|3G Studios|Sierra Entertainment|
|SWAT Elite Troops|2008|Mobile phones|Rovio Mobile|Vivendi Games Mobile|

Question: how many consecutive games were released in 2006?
Answer: 2